BARC/PUB/2012/0747

 
 

Monte Carlo simulation and measurement of X-ray dose from 9 MeV RF electron LINAC for cargo scanning

 
     
 
Author(s)

Chaudhary, N.; Bhattacharjee, D.; Yadav, V.; Sharma, S. D.; Acharya, S.; Dixit, K. P.; Mittal, K. C.
(A&PPD;RP&AD)

Source

Indian Journal of Pure & Applied Physics, 2012. Vol. 50 (7): pp. 517-519

ABSTRACT

The 9 MeV RF Electron Linear Accelerator (Linac) is operational at Electronic Corporation of India Limited (ECIL). Hyderabad to demonstrate cargo-scanning applications to prevent the transport of contraband objects. The interrogation is done by a fanned X-ray beam produced by impinging an energetic electron beam on tantalum (Ta) target. The desired dose rate for this purpose is 22 Gy/min at 1 m from the X-ray source. It is required to determine the X-ray dose rate at one meter distance from the X-ray converter for a given set of beam parameters. Monte Carlo simulations have been done for the X-ray dose rate measurement by using Geant4 software toolkit. X-ray dose rate values at 1 m distance from X-ray target have been estimated at various polar angles with respect to the direction of the incident beam. The plot shows angular distribution of significant X-ray intensity in a cone of 15° half-angle. The maximum X-ray emission is in the forward direction of the beam and the dose-rate is estimated to be 19.40 Gy/min when the beam parameters are (i) 9 MeV energy (ii) 60 mA peak beam current and (ill) 250 Hz pulse repetition frequency (PRF). Experiments have also been carried out using air ionization chamber to obtain X-ray dose-rate at 1 m distance from target The measured value without an electron­stopper after the target is 20.63 Gy/min at 1 m distance which is close to the required dose rate for the actual cargo scanning purpose. The simulated results also closely match with the experimental observations. implying that the present simulation model is suitable for the characterization of an X-ray source for cargo scanning applications

 
 
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